Forty-five minutes later, having reached 47,000 feet altitude, SS2 detached from WK2, fired up its rocket boosters and, over the course of 16 minutes' burn, blasted its way up to 55,000 feet at a speed hitting Mach 1.2. That accomplished, SS2 descended, returned to base, and landed safely -- the whole trip having taken just under one hour.

Both SS2 and its WK2 carrier are built by Virgin Galactic partner and Northrop Grumman subsidiary Scaled Composites of Mojave, Calif.

SS2 is now ready to enter its final phase of testing prior to beginning commercial service ferrying "space tourists" into suborbital visits to space. After a few more test runs, Virgin Galactic expects to begin commercial operations late this year.